Mercury-vapor arc rectifier of glass



Aug. 17 1926.

E. MARSCHNER unncum VAPOR ARC RECTIFIER 0F GLASS Filed Angus 5 Shoots-Shoot 1 Aug. 17 1926. 7 1,596,500

E. MARSCHNER MERCURY VAPOR ARC RECTIFIER OF GLASS.

Filed August 30, 1921 I5 Sheets-Shoot 2 Aug. 17 1926.

' E. MARSCHNER uancuay VAPOVR ARC RECTIFIER 0F cuss Filed August 30, 1921 3 Shoots-Shoot 5 WW Q was Aug. 17, 1926.

UNITED STATES EUGEN MABSCHNEB, OF WEIB SENSEE, NEAR BERLIN, GERMANY, ASSIGNOB T9 Gulf OE- PATENT- OFFICE.

BICHTEB-GESELLSCHAIT 3. E, OF BERLIN, GERMANY, A CORPORATION 01' onmumr.

MERCURY-VAPOR ARC RECTIFIER OI GLASS.

Application flled lugult so, 1921, Serial 110. 497,058, and in Germany m 27, 1019.

(GRANTED UNDER TEE PROVISIONS OF THE ACT 01' IABOK 8, 1921., 41 STAT. In, 1318.)

latinum insertions generally known can or security of serviceonly be made up to wire thicknesses of 2 to 2.5 mm. so that, with such current intensities, several wires mounted in parallel have to be used, rangement has the drawback that a uniform distribution of current can only be obtained with difiiculty and that the fusin can easily be disrupted, owing to over oading of the individual wires In contradistinction to this the subject of this invention is an electrode insertion, use bein made of a small platinum pot, closed 0 from the vacuum vessel, in a similar manner as already known in connection with Rontgen tubes. In comparison with the simple conditions revailing with Routgen tubes in the case 0? vacuum vessels, however, for mercury vapor-arc rectifiers, there must still be added the difliculties which are caused by the mercury, and this necessitates a deviation from the usual construction of the platinum pot. a

The drawing shows constructional examples of the invention.

Fi re 1 is a longitudinal section through an eId ctrode insertion, in which the electrode is an'anode.

Figure 2 shows a similar longitudinal section throu h an electrode insertion, where the elect e is a cathode.

Figure scale, a partial section through a modified constructional form. A

In Figure 1 a is the glass body which is turned over towards theinside at its open end. In this fold there is now fused in a small pot b of thin sheet platinum or of a platinum alloy. Owingto the density of the latinum this Kt afi'ords a certain and relia 1e air seal. e t b has a contacted neckfandabottom Uponthisbottom there is welded or soldered at one side the 8 shows, upon a largely increased conductor 0 to the anode q and, on the other pot itself of all the mechanical stresses pro duced by the unequal heating of the anode and prevents any inju to the ints of fusion. The conductor c to the :iectrode' or to the anode e consists of a metal, such asnickel for instance, which does not amal gamate with mercury, but which can be easily welded to platinum. A hard soldering of another metal, such for instance as iron which cannot be welded to platinum, is of no use, as the solderingoint would then be quickly destroyed by t e mercury. In the narrow neck f of the platinum pot there is soldered a strong lead 9 of a metal, such as copper for instance, which is a good conductor of heat and electricit The soldering is effected preferably with silver or other similar hard solder. In thiseway the, feed of current takes lace with safety without breaking throng the platinum layer. To improve the radiation of heat to the surrounding air the lead g is provided with several ribs h of sheet copper or simi in metal, to which at the same time the connection for the exterior lead is effected. In order to prevent oscillations or vibrations in case of shocks or tremors there is soldered means the lead is provided with a second point of support in addition to 'a cooperatmg guide nng m of thin sheet iron, which is shown adjacently connected to the electrode e. At this int the glass vessel a is preferably provided with a nick, whilst at 0, at a point which is sufliciently remote from the point of soldering on the platinum pot, the end of the glam vessel can be fused together with the remaining rtion of the glass vessel a. This type 0 construction facilitates the connection of the platinum pot with the conductors c and g.

' In the constructional form according to Figure 2 the type of the construction is substantially the same, but simpler, as the point of connection lies entirely within the mercury p. In place of the anode e a disc (1' is used as cathode. The conductor 0 could also consist of copper in both constructional forms, In this case it, together with the silver soldering, must be protected against the action of the mercury by means of a strong galvanic coating of some metal, such as iron or nickel, capable of resisting the action of mercury.

In the modified constructional form according to Figure 3 the pot I; does not consist of platinum but of nickel, or any other metal alloy free from platinum, but it must be absolutely free from-pores and its coeflicient of expansion must correspond as much as possible to that of the glass. In this case the potof nickel or other metal free from platinum must be provided at its edge, as far as it is fused into the turned -over neck of the glass vessel, with a coatin of pure platinum or platinum alloy whic is adapted to be fused together with glass. This coating can be galvanically deposited or electrically fused onto the other part. In Figure 3 g is the current conductor, 0 the lead connected with the electrode, and b is the platinum pot made of nickel for instance in this case, whilst a is the glass vessel. As far as the pot b is fused into the glass vessel, its edge is provided with the coating of platinum a: or the platinum alloy referred to.

Experiments have shown that an electrode insertion according to Figure 3, has the same good properties as that with the platinum pot according to Figures 1 or 2, but the high costs and difficulties connected with the use of platinum are obviated. Nickel is the most suitable material for this construction, said nickel being melted in vacuo in order to secure perfect freedom from pores. Of course in Figure 3 the coating 0: is shown in a greatly exaggerated scale for the sake of clearness.

A further constructional form of the electrode insertion according to the invention is based upon the recognition of the fact that the elastic pot, even if it does not consistof platinum, can be made without a coating of platinum or a platinum alloy at the point of insertion if, namely, use he made of a material melted in vacuo having a coeificient of expansion which corres onds to that ofplatinum. Nickel iron me ted in vacuo, or completely pure iron which has also been melted in vacuo, has been found to be a metal pre-eminently suitable for the purpose. v

' What I do claim as my invention and desire to secure by Letters Patent of the United States is .1. A mercury arc rectifier comprising a glass vessel containing an electrode and having a leading-in portion formed with an inwardly extending neck; a cup with elastic walls of thin platinum with its open end fused into the end of said neck and closing the latter; an external conductor of electricity and heat fused to said cup and extending past the joint between the cup and said inwardly extending neck; an internal conductor which does not amal amate with mercury extending from said e ectrode and also fused to said cup, thus uniting said conductors and cup in a practically integral structure; and means for supporting the external conductor independently of said cup so as to permit the use of conductor bars capable of carrying high tension currents.

2. A mercury arc rectifier comprising a glass vessel containing an electrode and having a leading-in portion formed with an inwardly extending neck; a on with elastic walls of thin platinum having its open end fused to the open end of said neck forming an extension of and closing the latter; an internal conductor bar capable of carrying a high tension current and which does not amalgamate with mercury connecting said electrode with said cup and fused to the latter; an external conductor of electricity and heat fused to said cup and extending out therefrom through said neck; and means supporting the external conductor independently of said cup together with means for aligning and guiding said internal conductor within the vessel under expansions and contractions to relieve supporting strain upon the cup.

3. In a mercury vapor arc rectifier of glass the combination of an elastic pot of thin sheet of platinum containing metal fused into the neck turned down upon itself of the glass body with a conductor for the electrode of a metal which does not amalgamate with mercury welded upon the bottom of said pot on the inner side of the glass vessel, an outward-leadin conductor of a metal which is a good con uetor of electricity and heat welded in the contracted neck-shaped part of the said pot on the outer side of the glass vessel, and a conical block clamped on the outward-leading conductor and fitting into a conical opening in a member connected to the glass vessel, sub stantially as set forth.

4. In a mercury vapor arc rectifier of glass the combination of an elastic pot of thin sheet of platinum containing metal fused into the neck turned down upon itself of the lass body with a conductor for the electroie of a metal which does not amalgamate with mercury welded upon the bottom of said pot on the inner side 0*? the glass vessel, an outward-leading conductor of a metal which is a good conductor of electricity and heat, welded in the contracted neck-she ed part of the said pot on the outer si e of the glass vessel, vanes on the outward-leading conductor adapted to carry OR the heat and to receive the connectin means for the external leads, and a conica 10 -block clamped on the outward-leading con ductor and fitting into a conical opemng in a member connected to the glass vessel; substantially as set' forth.

In testimony whereofl aflix my signature.

EUGEN MARSCHNER. 

